Description
Product Core Brief
- Model: 136711-01
- Brand: Bently Nevada
- Series: 3500 Machinery Protection System
- Core Function: Conditions signals from LVDTs, rotating potentiometers, and proximity probes for axial position and differential expansion monitoring.
- Product Type: Position I/O Module
- Key Specs: 3500/60 Compatible | Internal Terminations | DC LVDT/RPT Support
- Note: Verify sensor type and termination style (internal vs. external) against existing rack configuration.
Bently Nevada 133323-01
Key Technical Specifications
- Compatible Monitor: 3500/60 Position Monitor
- Sensor Compatibility: Eddy Current Probes, DC LVDT, Rotating Potentiometer (RPT)
- Termination Type: Internal (screw terminals on front of module)
- Measurement Functions: Axial Position, Differential Expansion, Eccentricity
- Operating Temp: -30 °C to +65 °C (-22 °F to +150 °F)
- Storage Temp: -40 °C to +85 °C (-40 °F to +185 °F)
- Humidity: 95% non-condensing
- Outputs: Buffered sensor outputs, 4-20 mA recorder outputs
- Mounting: 3500 Rack Backplane
Product Introduction
The Bently Nevada 136711-01 is a Position I/O module with internal terminations, designed specifically for the 3500/60 monitor. It provides precision signal conditioning for displacement sensors, enabling accurate measurement of axial position, differential expansion, and eccentricity in rotating machinery.
This module eliminates the need for external termination blocks, reducing panel wiring complexity and installation time. Its support for DC LVDTs and rotating potentiometers makes it ideal for steam turbine valve position and casing expansion monitoring applications.
QA & Testing SOP (Transparency Building)
- Incoming Inspection: Verify serial number traceability against OEM records; inspect front terminal block for stripped threads or corrosion; confirm anti-static packaging integrity.
- Live Testing: Install in 3500/60 test rack; verify OK LED and backplane communication; inject simulated LVDT and RPT signals to validate position scaling and alarm setpoints.
- Electrical Testing: Measure insulation resistance (>10 MΩ at 500VDC); verify ground continuity <0.1 Ω; check internal terminal block contact resistance.
- Firmware/Config Backup: Record exact firmware revision via 3500 Configuration Software; photograph all DIP switches and jumper settings before packing.
- Final QC & Packaging: Apply QC pass tag with test date; pack in OEM-spec anti-static bag with foam corner protectors; seal in individual box with documentation.
Installation Pitfalls & Guide (Engineer to Engineer)
❗ Firmware Rev Mismatch: Mixing revisions in a 3500/60 slot can cause position scaling errors or communication timeouts. Always match the exact revision of the replaced unit or update the entire frame via 3500 Configuration Software before commissioning.
❗ DIP Switch/Jumper Errors: Sensor type and wire configuration are critical. Take a high-res photo of the old module’s jumper settings before removal. Incorrect LVDT type or RPT configuration will cause significant position reading errors or complete signal loss.
❗ Wiring Incompatibilities: This module has INTERNAL terminations. Do not confuse with external termination variants. Verify your field wiring is routed directly to the front panel terminals, not to a separate terminal block.
❗ DC LVDT Channel Limitations: When using DC LVDTs, verify channel allocation. Not all channels may support DC excitation depending on module revision. Check the 3500/60 manual for specific channel limitations before installation.
❗ ESD Dangers: The position input stage is extremely ESD-sensitive. A single static discharge can destroy the precision signal conditioning circuitry. Always wear a grounded wrist strap connected to the rack chassis, not just the bench mat.
Replacement Procedure:
- Pre-install: Back up 3500/60 configuration; photograph jumpers; verify new unit revision and sensor type matches.
- Removal: Power down frame (3500/60 is NOT hot-swappable); wait 60s for capacitor discharge; disconnect field wires; remove module.
- Install: Set jumpers per photo; seat module firmly; reconnect field wires to internal terminals; torque to 0.5 Nm.
- Power-on Test: Apply power; verify OK LED; check 3500 Configuration Software for no faults; verify position readings against reference measurement.
FAQ (Frequently Asked Questions)
Q: Can I hot-swap the Bently Nevada 136711-01?
A: No. The 3500/60 Position I/O module lacks hot-swap circuitry. Removing it under power will cause a backplane voltage disturbance, potentially corrupting the configuration of adjacent monitoring modules and risking arc damage to the backplane connector. Always perform a controlled frame shutdown.
Q: Why is my new module showing incorrect position values?
A: Check the sensor type configuration first. If the module is set for AC LVDT but you’re using a DC LVDT (or RPT), the signal conditioning will be wrong. Also verify the LVDT excitation voltage and that the sensor is properly gapped. Incorrect jumper settings are the #1 cause of field errors.
Q: Is this module interchangeable with external termination variants?
A: No. The 136711-01 has INTERNAL terminations (wires connect directly to the module). External termination variants require separate terminal blocks. They are mechanically and electrically different. Verify your existing installation before ordering.
Q: What happens if I lose power to this module during operation?
A: You lose all position monitoring and protection for that channel group. The 3500/60 requires continuous power to process displacement signals and drive alarms. There is no battery backup. Always ensure redundant power supply configuration per API 670 for critical position parameters.
Q: How do I verify if this is a genuine Bently Nevada 136711-01?
A: Check for the Bently Nevada logo etched (not printed) on the PCB; verify the serial number matches the label; inspect the front terminal block for factory-installed screws (replaced screws indicate refurbishment). Request the OEM certificate of conformity from the supplier; reputable vendors provide traceability to the original Bently Nevada shipment.
Q: Can I use this module for vibration monitoring?
A: Yes, but only for radial vibration using proximity probes. For velocity or acceleration monitoring, use dedicated 3500/42 modules. The 136711-01 is optimized for displacement and position measurements; using it outside its intended application may compromise measurement accuracy.
Q: What’s the warranty on replacement units?
A: Standard warranty is 12 months from shipment date, covering manufacturing defects and DOA conditions. Warranty does not cover ESD damage, overvoltage from incorrect wiring, or physical damage from improper installation. Always retain the QC test report and original packaging for warranty claims.
